| Popis: |
The COVID-19 (Coronavirus Disease 2019) pandemic revealed many «blank spots» in epidemiology at that very moment when humanity became confident that all epidemic disasters had remained in the distant past. The aim of this article is to study COVID-19 pandemic as an indicator of «blank spots» in epidemiology and infectious pathology. The article substantiates that the COVID-19 epidemic started much earlier than it was identified and recognized in China. The failure to establish the primary natural reservoir of SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) among vertebrates suggests an expansion of searches for invertebrates. The reasons for the global spread of SARS-CoV-2 may be the presence of numerous unidentified primary and secondary natural foci of the virus among animals living close to humans, the high transmissibility of the virus and its presymptomatic transmission. High transmissibility of SARS-CoV-2 is possible because: the binding energy of S1 protein of the virus with its receptor ACE2 is higher than that of viruses of closely related species; the virus penetrates into the endosomes of the cells more efficiently; because of the work of the replication-transcription complex, which counteracts the innate protective response of cells. The presymptomatic transmission of SARSCoV-2, which has become the main reason for the pandemic spread of SARS-CoV-2, is a consequence of the late detection of the virus by the innate immune system. Infected individual becomes contagious first, and then the specific symptoms of the disease appear. It is suggested in the article, that the COVID-19 pandemic is not an independent event caused by the emergence of a «new virus» (like one more flu pandemic), but a manifestation of a more complex and dangerous phenomenon, i.e. a change of the phase of the centuries-old global pandemic cycle, when, due to the increase in the density of immunodeficient populations weakened by various pathologies (chronic diseases, accumulation of genetic defects, aging, etc.) and aggravated social problems, non-cyclic pandemics and cyclical low-contagious epidemics are replaced by cyclical ones caused by highly contagious pathogens. SARS-CoV-2 is not the last in these events. The severe clinical course of COVID-19 is caused by such poorly understood phenomena as «imbalance» of renin–angiotensin–aldosterone system, cytokine storm, septic course of the disease, the patient`s genetic factors and immunopathology, developed during the infectious process (antibodydependent enhancement enhancement of infection, antigenic imprinting, antiphospholipid syndrome and other factors). Filling these «blank spots» will catalyze a research revolution in epidemiology and infectious pathology. |
